Comparing your login credentials with millions of known leaked accounts that are major leaks means that Google monitors the dark network to some extent to collect passwords, most of which come from publicly available data obtained by crawlers.
If your password is included in the leaking behavior, Google will recommend that you change the affected password. Of course, Google will also use a weak password that is easy to crack to inform you about the security of your account.
To coincide with Cyber Security Awareness Month, Google and the Harris Poll collaborated to examine the password habits of Americans, and the results were worrying. Many users'passwords contain content with distinct personal characteristics, such as birthdays, pet names and so on. Few people talk about the advantages of additional security measures, such as two-factor authentication (only 37% of respondents use it) and password manager (15%).
Sixty-six percent of respondents said they used the same password for multiple online accounts. When it comes to sharing with important people, only 11 percent said they changed the Netflix (or other streaming service) password after the breakup.
Password reuse is the main thing Google wants to prevent, because using the same password for multiple services can put you in a terrible situation.